Cationic conditioning polymers meant for deposition onto negatively charged surfaces, such as fabric, skin, or hair, are included in many common consumer product compositions. Such products can provide consumer-desired benefits such as softness, lubricity, hand, anti-wrinkle, hair conditioning, frizz control, skin moisturization, and color protection. The effectiveness of any particular conditioning polymer depends not only upon the chemical and physical properties of the conditioning polymer itself, but also upon those of the targeted surface and the product formulation in which the conditioning polymer is delivered.
Many consumer products containing cationic conditioning polymers are in the form of aqueous-based rinse-off compositions, such as hair shampoos, body washes, laundry detergents, and fabric softeners. Despite the popularity of these rinse-off compositions, such product forms frequently experience difficulties effectively depositing these cationic conditioning polymers, which are typically hydrophobic, onto the target surfaces. Incorporating these conditioners into aqueous-based products often results in the conditioner being preferentially rinsed away from the intended site of deposition, rather than effectively deposited. This problem is particularly pronounced in the context of cleansing compositions containing surfactant, especially those containing anionic surfactant.
Anionic surfactants can interfere with deposition by forming complexes/precipitates with the cationic conditioning polymers. The higher the concentration of anionic surfactant, the more difficult it becomes to deposit cationic benefit actives. This leads to non-cost-effective use and waste of materials. Further, even if an acceptable level of deposition is attained, these formulations may lack shelf-stability due to flocculation and precipitation, making them unacceptable as consumer products.
Several materials exist in the art, but are not wholly satisfactory. For example, the material described by Ono (WO 99/32539) comprises functionalized end groups having heteroatoms such as oxygen, nitrogen, sulfur, or halogens. These functionalized end groups can lead to undesirable reactions that pose stability issues for compositions comprising these materials. For instance, Ono's silicones can react further through these end groups, leading to further condensation and/or polymerization of the silicones in the compositions during storage.
Also known in the art are quaternized silicones that include alkylene oxide units, such as those described by Masschelein (U.S. Pat. No. 6,903,061). The quaternized silicones described by Masschelein may be too water soluble for a given application, and thus can have a reduced capacity as conditioning polymers, since these materials tend to partition into water at a higher than desired level rather than deposit on the target substrate. Further, when these materials are used as the conditioning active, they can have an undesirable feel because of their high permeability to water and water vapor. Additionally, because of the potential for variability in the alkylene oxide moiety, these materials can be difficult to formulate reproducibly. This can limit the desired degree of functionality in a silicone material. It would desirable to have a material the provides greater flexibility via the level of quaternization. Similarly, the ethoxylated quaternized silicone materials disclosed by Boutique (U.S. Pat. No. 6,833,344) suffer from many of the same inadequacies of those described by Masschelein.
There is still a need to provide cationic conditioning polymers that are suitable for use in a wide range of consumer product applications. Applicant is not aware of any prior silicone polymer that meets the desired shelf-stability and performance criteria desired in a consumer product context. Accordingly, it is an object of the present invention to provide cationic conditioning polymers and consumer product compositions comprising conditioning polymers that can effectively deposit and provide conditioning benefits to negatively charged substrates while avoiding the aforementioned disadvantages.